1. Field of the Invention
This invention relates to an apparatus for controlling mechanical music-makers, such as player-pianos, nickelodeons, and reed organs, which utilize a vacuum as the motive force for pneumatically driving mechanical key actuators therein. More particularly, the invention relates to a valve system which can isolate the standard vacuum actuation system found in these mechanical music-makers and allow the utilization of an electrically controlled actuation system, which system may be controlled by a programmable microprocessor-based control apparatus.
2. Description of the Prior Art
Player-pianos, nickelodeons and reed organs are well-known and were popular in the early part of the Twentieth Century. These player-pianos utilized a vacuum system to control the mechanical actuation of the keys. In most player-pianos, for example, the vacuum is created by pedaling a suction bellows with the feet, which suction bellows is located in the lower portion of the piano. The vacuum produced was channeled through a manifold system into the upper area of the piano, where it was utilized to control individual valves of a pneumatic actuation system. The actuation system, itself, consisted of a multiplicity of small bellows, each having a push rod attached thereto. Each push rod operated a piano key when activated by a sudden collapse of the bellows as a result of an individual vacuum control valve opening and connecting the inside of the bellows to a vacuum, thereby allowing the air inside to escape.
These pneumatic valves were generally controlled by a tracker bar having a multiplicity of holes therein corresponding to each key of the piano. A player-piano paper roll having a plurality of perforations corresponding to a musical piece was then rotated across the tracker bar. When a hole on the player-piano roll overlies a hole in the tracker bar, the vacuum holding the pneumatic valve closed is vented via a tube which runs from the tracker bar to a vacuum side of the valve. The valve then opens allowing the vacuum manifold to be directly connected to the bellows thereby actuating the piano key and playing the corresponding note by striking the piano string with the hammer in the standard manner.
With the advent of electronically controlled pianos and music synthesizers, electronic devices have been developed which can produce or utilize a standardized MIDI output signal. These standardized signals can be pre-recorded on hard or soft floppy disks, or via pre-programmed MIDI hybrid chips or pre-recorded MIDI tape cassettes, which can act as an input for the production of the sounds of these electronic pianos and synthesizers. However, until the present invention, there has been no method by which a standard player-piano or nickelodeon could be controlled by a pre-recorded MIDI electronic signal. This is because, as described above, the control system for a player-piano or nickelodeon is exclusively mechanical and controlled exclusively by a pneumatic control system.